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2010-07-19tcp: fix crash in tcp_xmit_retransmit_queueIlpo Järvinen1-0/+3
It can happen that there are no packets in queue while calling tcp_xmit_retransmit_queue(). tcp_write_queue_head() then returns NULL and that gets deref'ed to get sacked into a local var. There is no work to do if no packets are outstanding so we just exit early. This oops was introduced by 08ebd1721ab8fd (tcp: remove tp->lost_out guard to make joining diff nicer). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Reported-by: Lennart Schulte <lennart.schulte@nets.rwth-aachen.de> Tested-by: Lennart Schulte <lennart.schulte@nets.rwth-aachen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-17tcp: tcp_synack_options() fix Eric Dumazet1-5/+4
Commit 33ad798c924b4a (tcp: options clean up) introduced a problem if MD5+SACK+timestamps were used in initial SYN message. Some stacks (old linux for example) try to negotiate MD5+SACK+TSTAMP sessions, but since 40 bytes of tcp options space are not enough to store all the bits needed, we chose to disable timestamps in this case. We send a SYN-ACK _without_ timestamp option, but socket has timestamps enabled and all further outgoing messages contain a TS block, all with the initial timestamp of the remote peer. Fix is to really disable timestamps option for the whole session. Reported-by: Bijay Singh <Bijay.Singh@guavus.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-16net: Introduce sk_route_nocapsEric Dumazet1-1/+1
TCP-MD5 sessions have intermittent failures, when route cache is invalidated. ip_queue_xmit() has to find a new route, calls sk_setup_caps(sk, &rt->u.dst), destroying the sk->sk_route_caps &= ~NETIF_F_GSO_MASK that MD5 desperately try to make all over its way (from tcp_transmit_skb() for example) So we send few bad packets, and everything is fine when tcp_transmit_skb() is called again for this socket. Since ip_queue_xmit() is at a lower level than TCP-MD5, I chose to use a socket field, sk_route_nocaps, containing bits to mask on sk_route_caps. Reported-by: Bhaskar Dutta <bhaskie@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-22tcp: fix outsegs stat for TSO segmentsTom Herbert1-2/+3
Account for TSO segments of an skb in TCP_MIB_OUTSEGS counter. Without doing this, the counter can be off by orders of magnitude from the actual number of segments sent. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-20net: Fix various endianness glitchesEric Dumazet1-2/+2
Sparse can help us find endianness bugs, but we need to make some cleanups to be able to more easily spot real bugs. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-15net: replace ipfragok with skb->local_dfShan Wei1-1/+1
As Herbert Xu said: we should be able to simply replace ipfragok with skb->local_df. commit f88037(sctp: Drop ipfargok in sctp_xmit function) has droped ipfragok and set local_df value properly. The patch kills the ipfragok parameter of .queue_xmit(). Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11tcp: Set CHECKSUM_UNNECESSARY in tcp_init_nondata_skbDavid S. Miller1-0/+1
Back in commit 04a0551c87363f100b04d28d7a15a632b70e18e7 ("loopback: Drop obsolete ip_summed setting") we stopped setting CHECKSUM_UNNECESSARY in the loopback xmit. This is because such a setting was a lie since it implies that the checksum field of the packet is properly filled in. Instead what happens normally is that CHECKSUM_PARTIAL is set and skb->csum is calculated as needed. But this was only happening for TCP data packets (via the skb->ip_summed assignment done in tcp_sendmsg()). It doesn't happen for non-data packets like ACKs etc. Fix this by setting skb->ip_summed in the common non-data packet constructor. It already is setting skb->csum to zero. But this reminds us that we still have things like ip_output.c's ip_dev_loopback_xmit() which sets skb->ip_summed to the value CHECKSUM_UNNECESSARY, which Herbert's patch teaches us is not valid. So we'll have to address that at some point too. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11inet: Remove unused send_check length argumentHerbert Xu1-1/+1
inet: Remove unused send_check length argument This patch removes the unused length argument from the send_check function in struct inet_connection_sock_af_ops. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Yinghai <yinghai.lu@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-0/+1
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-08tcp: Fix tcp_make_synack()Eric Dumazet1-9/+9
Commit 4957faad (TCPCT part 1g: Responder Cookie => Initiator), part of TCP_COOKIE_TRANSACTION implementation, forgot to correctly size synack skb in case user data must be included. Many thanks to Mika Pentillä for spotting this error. Reported-by: Penttillä Mika <mika.penttila@ixonos.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-23net: Add rtnetlink init_rcvwnd to set the TCP initial receive windowlaurent chavey1-4/+13
Add rtnetlink init_rcvwnd to set the TCP initial receive window size advertised by passive and active TCP connections. The current Linux TCP implementation limits the advertised TCP initial receive window to the one prescribed by slow start. For short lived TCP connections used for transaction type of traffic (i.e. http requests), bounding the advertised TCP initial receive window results in increased latency to complete the transaction. Support for setting initial congestion window is already supported using rtnetlink init_cwnd, but the feature is useless without the ability to set a larger TCP initial receive window. The rtnetlink init_rcvwnd allows increasing the TCP initial receive window, allowing TCP connection to advertise larger TCP receive window than the ones bounded by slow start. Signed-off-by: Laurent Chavey <chavey@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-23tcp: Remove check in __tcp_push_pending_framesKrishna Kumar1-5/+0
tcp_push checks tcp_send_head and calls __tcp_push_pending_frames, which again checks tcp_send_head, and this unnecessary check is done for every other caller of __tcp_push_pending_frames. Remove tcp_send_head check in __tcp_push_pending_frames and add the check to tcp_push_pending_frames. Other functions call __tcp_push_pending_frames only when tcp_send_head would evaluate to true. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-15tcp: Revert per-route SACK/DSACK/TIMESTAMP changes.David S. Miller1-13/+5
It creates a regression, triggering badness for SYN_RECV sockets, for example: [19148.022102] Badness at net/ipv4/inet_connection_sock.c:293 [19148.022570] NIP: c02a0914 LR: c02a0904 CTR: 00000000 [19148.023035] REGS: eeecbd30 TRAP: 0700 Not tainted (2.6.32) [19148.023496] MSR: 00029032 <EE,ME,CE,IR,DR> CR: 24002442 XER: 00000000 [19148.024012] TASK = eee9a820[1756] 'privoxy' THREAD: eeeca000 This is likely caused by the change in the 'estab' parameter passed to tcp_parse_options() when invoked by the functions in net/ipv4/tcp_minisocks.c But even if that is fixed, the ->conn_request() changes made in this patch series is fundamentally wrong. They try to use the listening socket's 'dst' to probe the route settings. The listening socket doesn't even have a route, and you can't get the right route (the child request one) until much later after we setup all of the state, and it must be done by hand. This stuff really isn't ready, so the best thing to do is a full revert. This reverts the following commits: f55017a93f1a74d50244b1254b9a2bd7ac9bbf7d 022c3f7d82f0f1c68018696f2f027b87b9bb45c2 1aba721eba1d84a2defce45b950272cee1e6c72a cda42ebd67ee5fdf09d7057b5a4584d36fe8a335 345cda2fd695534be5a4494f1b59da9daed33663 dc343475ed062e13fc260acccaab91d7d80fd5b2 05eaade2782fb0c90d3034fd7a7d5a16266182bb 6a2a2d6bf8581216e08be15fcb563cfd6c430e1e Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02tcp: sysctl_tcp_cookie_size needs to be exported to modules.David S. Miller1-0/+1
Otherwise: ERROR: "sysctl_tcp_cookie_size" [net/ipv6/ipv6.ko] undefined! make[1]: *** [__modpost] Error 1 Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02tcp: Fix warning on 64-bit.David S. Miller1-1/+1
net/ipv4/tcp_output.c: In function ‘tcp_make_synack’: net/ipv4/tcp_output.c:2488: warning: cast from pointer to integer of different size Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02TCPCT part 1g: Responder Cookie => InitiatorWilliam Allen Simpson1-17/+86
Parse incoming TCP_COOKIE option(s). Calculate <SYN,ACK> TCP_COOKIE option. Send optional <SYN,ACK> data. This is a significantly revised implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 Requires: TCPCT part 1a: add request_values parameter for sending SYNACK TCPCT part 1b: generate Responder Cookie secret TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS TCPCT part 1d: define TCP cookie option, extend existing struct's TCPCT part 1e: implement socket option TCP_COOKIE_TRANSACTIONS TCPCT part 1f: Initiator Cookie => Responder Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02TCPCT part 1f: Initiator Cookie => ResponderWilliam Allen Simpson1-30/+163
Calculate and format <SYN> TCP_COOKIE option. This is a significantly revised implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 Requires: TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS TCPCT part 1d: define TCP cookie option, extend existing struct's Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONSWilliam Allen Simpson1-0/+3
Define sysctl (tcp_cookie_size) to turn on and off the cookie option default globally, instead of a compiled configuration option. Define per socket option (TCP_COOKIE_TRANSACTIONS) for setting constant data values, retrieving variable cookie values, and other facilities. Move inline tcp_clear_options() unchanged from net/tcp.h to linux/tcp.h, near its corresponding struct tcp_options_received (prior to changes). This is a straightforward re-implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 These functions will also be used in subsequent patches that implement additional features. Requires: net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-02TCPCT part 1a: add request_values parameter for sending SYNACKWilliam Allen Simpson1-1/+2
Add optional function parameters associated with sending SYNACK. These parameters are not needed after sending SYNACK, and are not used for retransmission. Avoids extending struct tcp_request_sock, and avoids allocating kernel memory. Also affects DCCP as it uses common struct request_sock_ops, but this parameter is currently reserved for future use. Signed-off-by: William.Allen.Simpson@gmail.com Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-23net/ipv4: Move && and || to end of previous lineJoe Perches1-2/+2
On Sun, 2009-11-22 at 16:31 -0800, David Miller wrote: > It should be of the form: > if (x && > y) > > or: > if (x && y) > > Fix patches, rather than complaints, for existing cases where things > do not follow this pattern are certainly welcome. Also collapsed some multiple tabs to single space. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-29Allow to turn off TCP window scale opt per routeGilad Ben-Yossef1-2/+4
Add and use no window scale bit in the features field. Note that this is not the same as setting a window scale of 0 as would happen with window limit on route. Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com> Sigend-off-by: Ori Finkelman <ori@comsleep.com> Sigend-off-by: Yony Amit <yony@comsleep.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-29Allow disabling TCP timestamp options per routeGilad Ben-Yossef1-2/+6
Implement querying and acting upon the no timestamp bit in the feature field. Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com> Sigend-off-by: Ori Finkelman <ori@comsleep.com> Sigend-off-by: Yony Amit <yony@comsleep.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-29Add the no SACK route option featureGilad Ben-Yossef1-1/+3
Implement querying and acting upon the no sack bit in the features field. Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com> Sigend-off-by: Ori Finkelman <ori@comsleep.com> Sigend-off-by: Yony Amit <yony@comsleep.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-18inet: rename some inet_sock fieldsEric Dumazet1-2/+2
In order to have better cache layouts of struct sock (separate zones for rx/tx paths), we need this preliminary patch. Goal is to transfert fields used at lookup time in the first read-mostly cache line (inside struct sock_common) and move sk_refcnt to a separate cache line (only written by rx path) This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr, sport and id fields. This allows a future patch to define these fields as macros, like sk_refcnt, without name clashes. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-01IPv4 TCP fails to send window scale option when window scale is zeroOri Finkelman1-5/+6
Acknowledge TCP window scale support by inserting the proper option in SYN/ACK and SYN headers even if our window scale is zero. This fixes the following observed behavior: 1. Client sends a SYN with TCP window scaling option and non zero window scale value to a Linux box. 2. Linux box notes large receive window from client. 3. Linux decides on a zero value of window scale for its part. 4. Due to compare against requested window scale size option, Linux does not to send windows scale TCP option header on SYN/ACK at all. With the following result: Client box thinks TCP window scaling is not supported, since SYN/ACK had no TCP window scale option, while Linux thinks that TCP window scaling is supported (and scale might be non zero), since SYN had TCP window scale option and we have a mismatched idea between the client and server regarding window sizes. Probably it also fixes up the following bug (not observed in practice): 1. Linux box opens TCP connection to some server. 2. Linux decides on zero value of window scale. 3. Due to compare against computed window scale size option, Linux does not to set windows scale TCP option header on SYN. With the expected result that the server OS does not use window scale option due to not receiving such an option in the SYN headers, leading to suboptimal performance. Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com> Signed-off-by: Ori Finkelman <ori@comsleep.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-02tcp: replace hard coded GFP_KERNEL with sk_allocationWu Fengguang1-2/+3
This fixed a lockdep warning which appeared when doing stress memory tests over NFS: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock mount_root => nfs_root_data => tcp_close => lock sk_lock => tcp_send_fin => alloc_skb_fclone => page reclaim David raised a concern that if the allocation fails in tcp_send_fin(), and it's GFP_ATOMIC, we are going to yield() (which sleeps) and loop endlessly waiting for the allocation to succeed. But fact is, the original GFP_KERNEL also sleeps. GFP_ATOMIC+yield() looks weird, but it is no worse the implicit sleep inside GFP_KERNEL. Both could loop endlessly under memory pressure. CC: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> CC: David S. Miller <davem@davemloft.net> CC: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-23Merge branch 'master' of ↵David S. Miller1-1/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/iwmc3200wifi/netdev.c net/wireless/scan.c
2009-07-23TCP: Add comments to (near) all functions in tcp_output.c v3Andi Kleen1-14/+44
While looking for something else I spent some time adding one liner comments to the tcp_output.c functions that didn't have any. That makes the comments more consistent. I hope I documented everything right. No code changes. v2: Incorporated feedback from Ilpo. v3: Change style of one liner comments, add a few more comments. Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20tcp: Fix MD5 signature checking on IPv4 mapped socketsJohn Dykstra1-1/+1
Fix MD5 signature checking so that an IPv4 active open to an IPv6 socket can succeed. In particular, use the correct address family's signature generation function for the SYN/ACK. Reported-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: John Dykstra <john.dykstra1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-29tcp: Stop non-TSO packets morphing into TSOHerbert Xu1-1/+2
If a socket starts out on a non-TSO route, and then switches to a TSO route, then the tail on the tx queue can morph into a TSO packet, causing mischief because the rest of the stack does not expect a partially linear TSO packet. This patch fixes this by ensuring that skb->ip_summed is set to CHECKSUM_PARTIAL before declaring a packet as TSO. Reported-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03net: skb->dst accessorsEric Dumazet1-1/+1
Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-04tcp: extend ECN sysctl to allow server-side only ECNIlpo Järvinen1-1/+1
This should be very safe compared with full enabled, so I see no reason why it shouldn't be done right away. As ECN can only be negotiated if the SYN sending party is also supporting it, somebody in the loop probably knows what he/she is doing. If SYN does not ask for ECN, the server side SYN-ACK is identical to what it is without ECN. Thus it's quite safe. The chosen value is safe w.r.t to existing configs which choose to currently set manually either 0 or 1 but silently upgrades those who have not explicitly requested ECN off. Whether to just enable both sides comes up time to time but unless that gets done now we can at least make the servers aware of ECN already. As there are some known problems to occur if ECN is enabled, it's currently questionable whether there's any real gain from enabling clients as servers mostly won't support it anyway (so we'd hit just the negative sides). After enabling the servers and getting that deployed, the client end enable really has some potential gain too. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-20tcp: fix mid-wq adjustment helperIlpo Järvinen1-1/+1
Just noticed while doing some new work that the recent mid-wq adjustment logic will misbehave when FACK is not in use (happens either due sysctl'ed off or auto-detected reordering) because I forgot the relevant TCPCB tagbit. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-02tcp: miscounts due to tcp_fragment pcount resetIlpo Järvinen1-1/+6
It seems that trivial reset of pcount to one was not sufficient in tcp_retransmit_skb. Multiple counters experience a positive miscount when skb's pcount gets lowered without the necessary adjustments (depending on skb's sacked bits which exactly), at worst a packets_out miscount can crash at RTO if the write queue is empty! Triggering this requires mss change, so bidir tcp or mtu probe or like. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Tested-by: Uwe Bugla <uwe.bugla@gmx.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-02tcp: add helper for counter tweaking due mid-wq changeIlpo Järvinen1-32/+34
We need full-scale adjustment to fix a TCP miscount in the next patch, so just move it into a helper and call for that from the other places. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-15tcp: simplify tcp_current_mssIlpo Järvinen1-34/+7
There's very little need for most of the callsites to get tp->xmit_goal_size updated. That will cost us divide as is, so slice the function in two. Also, the only users of the tp->xmit_goal_size are directly behind tcp_current_mss(), so there's no need to store that variable into tcp_sock at all! The drop of xmit_goal_size currently leaves 16-bit hole and some reorganization would again be necessary to change that (but I'm aiming to fill that hole with u16 xmit_goal_size_segs to cache the results of the remaining divide to get that tso on regression). Bring xmit_goal_size parts into tcp.c Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-15tcp: remove pointless .dsack/.num_sacks codeIlpo Järvinen1-2/+1
In the pure assignment case, the earlier zeroing is still in effect. David S. Miller raised concerns if the ifs are there to avoid dirtying cachelines. I came to these conclusions: > We'll be dirty it anyway (now that I check), the first "real" statement > in tcp_rcv_established is: > > tp->rx_opt.saw_tstamp = 0; > > ...that'll land on the same dword. :-/ > > I suppose the blocks are there just because they had more complexity > inside when they had to calculate the eff_sacks too (maybe it would > have been better to just remove them in that drop-patch so you would > have had less head-ache :-)). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: tcp_init_wl / tcp_update_wl argument cleanupHantzis Fotis1-1/+1
The above functions from include/net/tcp.h have been defined with an argument that they never use. The argument is 'u32 ack' which is never used inside the function body, and thus it can be removed. The rest of the patch involves the necessary changes to the function callers of the above two functions. Signed-off-by: Hantzis Fotis <xantzis@ceid.upatras.gr> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: get rid of two unnecessary u16s in TCP skb flags copyingIlpo Järvinen1-2/+2
I guess these fields were one day 16-bit in the struct but nowadays they're just using 8 bits anyway. This is just a precaution, didn't result any change in my case but who knows what all those varying gcc versions & options do. I've been told that 16-bit is not so nice with some cpus. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: kill eff_sacks "cache", the sole user can calculate itselfIlpo Järvinen1-6/+6
Also fixes insignificant bug that would cause sending of stale SACK block (would occur in some corner cases). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: drop unnecessary local var in collapseIlpo Järvinen1-5/+2
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: fix corner case issue in segmentation during rexmittingIlpo Järvinen1-0/+2
If cur_mss grew very recently so that the previously G/TSOed skb now fits well into a single segment it would get send up in parts unless we calculate # of segments again. This corner-case could happen eg. after mtu probe completes or less than previously sack blocks are required for the opposite direction. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: Don't clear hints when tcp_fragmentingIlpo Järvinen1-1/+6
1) We didn't remove any skbs, so no need to handle stale refs. 2) scoreboard_skb_hint is trivial, no timestamps were changed so no need to clear that one 3) lost_skb_hint needs tweaking similar to that of tcp_sacktag_one(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: deferring in middle of queue makes very little senseIlpo Järvinen1-0/+4
If skb can be sent right away, we certainly should do that if it's in the middle of the queue because it won't get more data into it. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02tcp: don't backtrack to sacked skbsIlpo Järvinen1-1/+1
Backtracking to sacked skbs is a horrible performance killer since the hint cannot be advanced successfully past them... ...And it's totally unnecessary too. In theory this is 2.6.27..28 regression but I doubt anybody can make .28 to have worse performance because of other TCP improvements. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-24Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller1-1/+0
2009-02-21tcp: Always set urgent pointer if it's beyond snd_nxtHerbert Xu1-4/+8
Our TCP stack does not set the urgent flag if the urgent pointer does not fit in 16 bits, i.e., if it is more than 64K from the sequence number of a packet. This behaviour is different from the BSDs, and clearly contradicts the purpose of urgent mode, which is to send the notification (though not necessarily the associated data) as soon as possible. Our current behaviour may in fact delay the urgent notification indefinitely if the receiver window does not open up. Simply matching BSD however may break legacy applications which incorrectly rely on the out-of-band delivery of urgent data, and conversely the in-band delivery of non-urgent data. Alexey Kuznetsov suggested a safe solution of following BSD only if the urgent pointer itself has not yet been transmitted. This way we guarantee that when the remote end sees the packet with non-urgent data marked as urgent due to wrap-around we would have advanced the urgent pointer beyond, either to the actual urgent data or to an as-yet untransmitted packet. The only potential downside is that applications on the remote end may see multiple SIGURG notifications. However, this would occur anyway with other TCP stacks. More importantly, the outcome of such a duplicate notification is likely to be harmless since the signal itself does not carry any information other than the fact that we're in urgent mode. Thanks to Ilpo Järvinen for fixing a critical bug in this and Jeff Chua for reporting that bug. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-18tcp: remove obsoleted comment about different passesIlpo Järvinen1-1/+0
This is obsolete since the passes got combined. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-05Revert "tcp: Always set urgent pointer if it's beyond snd_nxt"David S. Miller1-8/+4
This reverts commit 64ff3b938ec6782e6585a83d5459b98b0c3f6eb8. Jeff Chua reports that it breaks rlogin for him. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-25tcp: Always set urgent pointer if it's beyond snd_nxtHerbert Xu1-4/+8
Our TCP stack does not set the urgent flag if the urgent pointer does not fit in 16 bits, i.e., if it is more than 64K from the sequence number of a packet. This behaviour is different from the BSDs, and clearly contradicts the purpose of urgent mode, which is to send the notification (though not necessarily the associated data) as soon as possible. Our current behaviour may in fact delay the urgent notification indefinitely if the receiver window does not open up. Simply matching BSD however may break legacy applications which incorrectly rely on the out-of-band delivery of urgent data, and conversely the in-band delivery of non-urgent data. Alexey Kuznetsov suggested a safe solution of following BSD only if the urgent pointer itself has not yet been transmitted. This way we guarantee that when the remote end sees the packet with non-urgent data marked as urgent due to wrap-around we would have advanced the urgent pointer beyond, either to the actual urgent data or to an as-yet untransmitted packet. The only potential downside is that applications on the remote end may see multiple SIGURG notifications. However, this would occur anyway with other TCP stacks. More importantly, the outcome of such a duplicate notification is likely to be harmless since the signal itself does not carry any information other than the fact that we're in urgent mode. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>